The metabolism of platelet-activating factor in human T-lymphocytes.
The metabolism of 1-[3H]alkyl-2-acetyl-sn-glycero-3-phosphocholine (1-[3H]alkyl-2-acetyl-GPC; platelet-activating factor; PAF) was investigated in purified human peripheral blood T-lymphocytes and a human leukemia cell line of T-cell origin (MOLT-4). The major metabolic products of T-lymphocyte PAF metabolism are 1-alkyl-2-acyl-GPC, 1-alkyl-2-lyso-GPC and neutral lipid. The pattern of PAF metabolism in peripheral blood T-lymphocytes and MOLT-4 lymphoblasts was similar, although MOLT-4 lymphoblasts transformed PAF to 1-alkyl-2-acyl-GPC faster than peripheral blood T-lymphocytes (67% vs. 21% of added label after 64 min at 37 degrees C, respectively). Pre-exposure of MOLT-4 lymphoblasts to 1 mM of the serine hydrolase inhibitor phenylmethylsulfonyl fluoride resulted in an inhibition of PAF metabolism. Our results indicate that intact T-lymphocytes actively metabolize this biologically active phospholipid by the deacetylation-transacylation pathway.
Travers
J B
JB
Department of Pharmacology, College of Medicine, Ohio State University, Columbus 43210.
Sprecher
H
H
Fertel
R H
RH
D002460:Cell Line; D002855:Chromatography, Thin Layer; D006801:Humans; D007700:Kinetics; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*
D010972:Platelet Activating Factor; D010664:Phenylmethylsulfonyl Fluoride